input: sensors: add hall sensor for msm8909 SKUE

Hall sensor driver

Hall sensor is a switch. It senses magnetic field change and trigger interrupts to cpu.

Required properties:

 - compatible		: Should be "hall-switch".

 - pinctrl-names	: Pinctrl configuration names of this sensor driver.

				Should be "default".

 - interrupt-parent	: Parent of interrupt.

 - interrupts		: Hall Sensor interrupts to indicate new data ready or events.

 - vddio-supply		: Analog power supply needed to power device.

 - linux,gpio-int	: Irq gpio which is to provide interrupts to host.

 - linux,min-uv		: Device required minimum voltage.

 - linux,max-uv		: Device required max voltage.

Optional properties:

 - linux,wakeup		: Boolean to select interrupt wakeup or not, if this property is defined

				device will wakeup system.

Example:

 &soc {

	hall {

		compatible = "hall-switch";

		pinctrl-names = "default";

		pinctrl-0 = <&hall_sensor_int_default>;

		interrupt-parent = <&msm_gpio>;

		interrupts = <36 0x2003>;

		vddio-supply = <&pm8909_l6>;

		linux,gpio-int = <&msm_gpio 36 0x1>;

		linux,wakeup;

		linux,min-uv = <1650000>;

		linux,max-uv = <3300000>;

	};

 };

/*

 *

 * Copyright (c) 2014-2015, The Linux Foundation. All rights reserved.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 and

 * only version 2 as published by the Free Software Foundation.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 */

#include <linux/err.h>

#include <linux/errno.h>

#include <linux/input.h>

#include <linux/irq.h>

#include <linux/gpio.h>

#include <linux/interrupt.h>

#include <linux/slab.h>

#include <linux/pm.h>

#include <linux/module.h>

#include <linux/regulator/consumer.h>

#include <linux/of_gpio.h>

#include <linux/platform_device.h>

#define	LID_DEV_NAME	"hall_sensor"

#define HALL_INPUT	"/dev/input/hall_dev"

struct hall_data {

	int gpio;	/* device use gpio number */

	int irq;	/* device request irq number */

	int active_low;	/* gpio active high or low for valid value */

	bool wakeup;	/* device can wakeup system or not */

	struct input_dev *hall_dev;

	struct regulator *vddio;

	u32 min_uv;	/* device allow minimum voltage */

	u32 max_uv;	/* device allow max voltage */

};

static irqreturn_t hall_interrupt_handler(int irq, void *dev)

{

	int value;

	struct hall_data *data = dev;

	value = (gpio_get_value_cansleep(data->gpio) ? 1 : 0) ^

		data->active_low;

	if (value) {

		input_report_switch(data->hall_dev, SW_LID, 0);

		dev_dbg(&data->hall_dev->dev, "far\n");

	} else {

		input_report_switch(data->hall_dev, SW_LID, 1);

		dev_dbg(&data->hall_dev->dev, "near\n");

	}

	input_sync(data->hall_dev);

	return IRQ_HANDLED;

}

static int hall_input_init(struct platform_device *pdev,

		struct hall_data *data)

{

	int err = -1;

	data->hall_dev = devm_input_allocate_device(&pdev->dev);

	if (!data->hall_dev) {

		dev_err(&data->hall_dev->dev,

				"input device allocation failed\n");

		return -EINVAL;

	}

	data->hall_dev->name = LID_DEV_NAME;

	data->hall_dev->phys = HALL_INPUT;

	__set_bit(EV_SW, data->hall_dev->evbit);

	__set_bit(SW_LID, data->hall_dev->swbit);

	err = input_register_device(data->hall_dev);

	if (err < 0) {

		dev_err(&data->hall_dev->dev,

				"unable to register input device %s\n",

				LID_DEV_NAME);

		return err;

	}

	return 0;

}

static int hall_config_regulator(struct platform_device *dev, bool on)

{

	struct hall_data *data = dev_get_drvdata(&dev->dev);

	int rc = 0;

	if (on) {

		data->vddio = devm_regulator_get(&dev->dev, "vddio");

		if (IS_ERR(data->vddio)) {

			rc = PTR_ERR(data->vddio);

			dev_err(&dev->dev, "Regulator vddio get failed rc=%d\n",

					rc);

			data->vddio = NULL;

			return rc;

		}

		if (regulator_count_voltages(data->vddio) > 0) {

			rc = regulator_set_voltage(

					data->vddio,

					data->min_uv,

					data->max_uv);

			if (rc) {

				dev_err(&dev->dev, "Regulator vddio Set voltage failed rc=%d\n",

						rc);

				goto deinit_vregs;

			}

		}

		return rc;

	} else {

		goto deinit_vregs;

	}

deinit_vregs:

	if (regulator_count_voltages(data->vddio) > 0)

		regulator_set_voltage(data->vddio, 0, data->max_uv);

	return rc;

}

static int hall_set_regulator(struct platform_device *dev, bool on)

{

	struct hall_data *data = dev_get_drvdata(&dev->dev);

	int rc = 0;

	if (on) {

		if (!IS_ERR_OR_NULL(data->vddio)) {

			rc = regulator_enable(data->vddio);

			if (rc) {

				dev_err(&dev->dev, "Enable regulator vddio failed rc=%d\n",

					rc);

				goto disable_regulator;

			}

		}

		return rc;

	} else {

		if (!IS_ERR_OR_NULL(data->vddio)) {

			rc = regulator_disable(data->vddio);

			if (rc)

				dev_err(&dev->dev, "Disable regulator vddio failed rc=%d\n",

					rc);

		}

		return 0;

	}

disable_regulator:

	if (!IS_ERR_OR_NULL(data->vddio))

		regulator_disable(data->vddio);

	return rc;

}

#ifdef CONFIG_OF

static int hall_parse_dt(struct device *dev, struct hall_data *data)

{

	unsigned int tmp;

	u32 tempval;

	int rc;

	struct device_node *np = dev->of_node;

	data->gpio = of_get_named_gpio_flags(dev->of_node,

			"linux,gpio-int", 0, &tmp);

	if (!gpio_is_valid(data->gpio)) {

		dev_err(dev, "hall gpio is not valid\n");

		return -EINVAL;

	}

	data->active_low = tmp & OF_GPIO_ACTIVE_LOW ? 0 : 1;

	data->wakeup = of_property_read_bool(np, "linux,wakeup");

	rc = of_property_read_u32(np, "linux,max-uv", &tempval);

	if (rc) {

		dev_err(dev, "unable to read max-uv\n");

		return -EINVAL;

	}

	data->max_uv = tempval;

	rc = of_property_read_u32(np, "linux,min-uv", &tempval);

	if (rc) {

		dev_err(dev, "unable to read min-uv\n");

		return -EINVAL;

	}

	data->min_uv = tempval;

	return 0;

}

#else

static int hall_parse_dt(struct device *dev, struct hall_data *data)

{

	return -EINVAL;

}

#endif

static int hall_driver_probe(struct platform_device *dev)

{

	struct hall_data *data;

	int err = 0;

	int irq_flags;

	dev_dbg(&dev->dev, "hall_driver probe\n");

	data = devm_kzalloc(&dev->dev, sizeof(struct hall_data), GFP_KERNEL);

	if (data == NULL) {

		err = -ENOMEM;

		dev_err(&dev->dev,

				"failed to allocate memory %d\n", err);

		goto exit;

	}

	dev_set_drvdata(&dev->dev, data);

	if (dev->dev.of_node) {

		err = hall_parse_dt(&dev->dev, data);

		if (err < 0) {

			dev_err(&dev->dev, "Failed to parse device tree\n");

			goto exit;

		}

	} else if (dev->dev.platform_data != NULL) {

		memcpy(data, dev->dev.platform_data, sizeof(*data));

	} else {

		dev_err(&dev->dev, "No valid platform data.\n");

		err = -ENODEV;

		goto exit;

	}

	err = hall_input_init(dev, data);

	if (err < 0) {

		dev_err(&dev->dev, "input init failed\n");

		goto exit;

	}

	if (!gpio_is_valid(data->gpio)) {

		dev_err(&dev->dev, "gpio is not valid\n");

		err = -EINVAL;

		goto exit;

	}

	irq_flags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING

		| IRQF_ONESHOT;

	err = gpio_request_one(data->gpio, GPIOF_DIR_IN, "hall_sensor_irq");

	if (err) {

		dev_err(&dev->dev, "unable to request gpio %d\n", data->gpio);

		goto exit;

	}

	data->irq = gpio_to_irq(data->gpio);

	err = devm_request_threaded_irq(&dev->dev, data->irq, NULL,

			hall_interrupt_handler,

			irq_flags, "hall_sensor", data);

	if (err < 0) {

		dev_err(&dev->dev, "request irq failed : %d\n", data->irq);

		goto free_gpio;

	}

	device_init_wakeup(&dev->dev, data->wakeup);

	enable_irq_wake(data->irq);

	err = hall_config_regulator(dev, true);

	if (err < 0) {

		dev_err(&dev->dev, "Configure power failed: %d\n", err);

		goto free_irq;

	}

	err = hall_set_regulator(dev, true);

	if (err < 0) {

		dev_err(&dev->dev, "power on failed: %d\n", err);

		goto err_regulator_init;

	}

	return 0;

err_regulator_init:

	hall_config_regulator(dev, false);

free_irq:

	disable_irq_wake(data->irq);

	device_init_wakeup(&dev->dev, 0);

free_gpio:

	gpio_free(data->gpio);

exit:

	return err;

}

static int hall_driver_remove(struct platform_device *dev)

{

	struct hall_data *data = dev_get_drvdata(&dev->dev);

	disable_irq_wake(data->irq);

	device_init_wakeup(&dev->dev, 0);

	if (data->gpio)

		gpio_free(data->gpio);

	hall_set_regulator(dev, false);

	hall_config_regulator(dev, false);

	return 0;

}

static struct platform_device_id hall_id[] = {

	{LID_DEV_NAME, 0 },

	{ },

};

#ifdef CONFIG_OF

static struct of_device_id hall_match_table[] = {

	{.compatible = "hall-switch", },

	{ },

};

#endif

static struct platform_driver hall_driver = {

	.driver = {

		.name = LID_DEV_NAME,

		.owner = THIS_MODULE,

		.of_match_table = of_match_ptr(hall_match_table),

	},

	.probe = hall_driver_probe,

	.remove = hall_driver_remove,

	.id_table = hall_id,

};

static int __init hall_init(void)

{

	return platform_driver_register(&hall_driver);

}

static void __exit hall_exit(void)

{

	platform_driver_unregister(&hall_driver);

}

module_init(hall_init);

module_exit(hall_exit);

MODULE_DESCRIPTION("Hall sensor driver");

MODULE_LICENSE("GPL v2");